1. Field of the Invention
Because of a perceived shortage of crude mineral oil from which to manufacture motor fuel or gasoline, significant industry efforts have been made to expand the supply of liquid motor fuel by manufacturing gasohol, which is a mixture of ethyl alcohol and of hydrocarbons boiling in the motor fuel boiling range. The ethyl alcohol employed in the manufacture of gasohol is generally obtained from the fermentation of grains or starchy raw materials. The production of ethyl alcohol by means of the fermentation of the noted raw materials results in the production of a relatively impure ethyl alcohol mixture containing a substantial amount of water.
Impure ethyl alcohol containing a substantial amount of water is not suitable for use in the manufacture of a gasohol fuel composition. The reason is that the three components of this normally liquid composition are not mutually soluble under all conditions of temperature and concentration variables. This fuel composition will separate into two phases under some conditions and the resultant two phase fuel supply will have an adverse effect on the operation of an internal combustion engine. It is a conventional practice to refine the crude ethyl alcohol by various treating means, such as by distillation to remove substantially all of the water therefrom in order to blend a relatively dry, i.e. less than about 0.5 weight percent water-containing ethanol. However, this procedure is relatively energy intensive and some observers question the energy conservation effectiveness of producing a gasohol fuel composition.
It is an object of the present invention to provide a novel method for treating ethanol containing substantial amounts of water.
Another object of the invention is to provide a method for upgrading crude ethanol for use in a gasohol mixture.
Another object of the invention is to provide a method for converting a substantial amount of the water content in a methanol mixture to an oxygenated organic compound compatible with a gasohol fuel composition.
It is a further object of this invention to provide an energy conserving method for treating a water-containing ethanol mixture.
The objects of this invention are realized in a method for treating an aqueous ethanol mixture which comprises mixing said aqueous ethanol mixture with a hydrocarbon fraction containing a substantial proportion of an aliphatic olefin having from 3 to 5 carbon atoms to form an ethanol-hydrocarbon fraction admixture, and contacting said ethanol-hydrocarbon fraction admixture with an acidic ion exchange resin catalyst to convert a substantial proportion of said contained water to an oxygenated compound.